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On 2011-08-01 19:49, James wrote: |
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> Sorry for delayed response, I've been reading up |
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> on gpt-fdisk [1]. |
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> Interesting reading on gpt-patch-fdisk.... |
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Thanks for the link; I haven't done such a thorough investigation as you |
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seem to have done... :-) |
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> So "parted" 2.3 in on the minimal cd I'm using: |
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> install-amd64-minimal-20110714.iso |
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> should be as sufficient as gparted? |
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As long as it has support for GPT and 4k-disks it should be sufficient... |
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> If so, it looks like my disk(s) setups |
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> which are identical are ok? [2] seems to |
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Ok or not... do they work as intended? If so I would say they work |
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fine... If you are asking if they are optimised or not I can honestly |
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say: I don't know. Also, if what you are after is an optimised setup for |
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your particular needs then you need to take into account the file system |
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(and, if so required, raid and/or lvm system setup). Which leads this |
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into a whole world of things to work out (workloads/usage patterns)... |
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You need to decide how much time you want to spend on optimising this... |
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Myself, I've given up on that. But since you're doing a raid 1 setup |
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(mirrored) I assume the theoretical limit (i.e. MB/s) would be the |
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individual disks. |
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> suggest that what I originally used (fdisk) |
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> to partition a 4K block drive |
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> (fdisk -H 224 -S 56 -l) will |
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> work, but the drive is NOT optimized? |
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This[*1] seems to suggest that the above fdisk line will create |
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partition aligned to 128k boundaries (excepting the first partition |
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which is aligned to 4k) for SSDs... again, haven't delved into the |
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breadth and depth needed for this to say something with something with |
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authority... :-) |
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[*1] |
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http://www.linuxfoundation.org/news-media/blogs/browse/2009/02/aligning-filesystems-ssd%E2%80%99s-erase-block-size |
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> (parted) print |
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> Model: ATA ST32000542AS (scsi) |
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> Disk /dev/sda: 2000GB |
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> Sector size (logical/physical): 512B/512B |
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^^^^^^^^^ |
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Hm... this may be an indication that the disks are "lying" to the kernel |
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about it's physical layout, telling it that it's a 512B sector size disk |
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when it's really a 4k sector disk... But I think parted can align |
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correctly anyway... see below Gentoo forum link for details... |
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> Partition Table: msdos |
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^^^^^ |
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This seems to suggest you are using MBR and not GPT, if that's what you |
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wanted (the size of your disks suggests you don't need GPT - <=2TB is |
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fine with MBR, only with sizes >2TB you need GPT)... I think that parted |
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can change the partition layout to GPT if you really want, but I don't |
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have it installed currently since I used the Gentoo live cd to |
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partition/install so I can't check on which command to perform that. |
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However, a word of caution: If you're trying to boot from a GPT disk |
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then you need (U)EFI firmware as opposed to "regular" bios (I think)... |
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For booting from an GPT disk there are some other hiccups as well, which |
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I've discovered, in that you _may_ need something called an EFI System |
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Partition, which is a VFAT formatted partition which is reserved for the |
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(U)EFI firmware (my system wouldn't boot without it - although I'm using |
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an SASWT4I "fake" raid card from Intel and GRUB2, which may have |
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complicated things...). |
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> Number Start End Size Type File system Flags |
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> 1 1049kB 269MB 268MB primary boot, raid |
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> 2 269MB 5414MB 5144MB primary raid |
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> 3 5414MB 2000GB 1995GB primary raid |
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> |
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> and |
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> (parted) align-check minimal 1 |
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> 1 aligned |
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> (parted) align-check optimal 1 |
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> 1 aligned |
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> (parted) align-check optimal 2 |
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> 2 aligned |
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> (parted) align-check optimal 3 |
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> 3 aligned |
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> (parted) |
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Hm... afaik the alignment issue is digital; either it's aligned (to 4k |
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or whatever) or it's not... as long as the tool used can handle it there |
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shouldn't be any differences (fdisk/gdisk/parted). That said, I think |
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that parted always issues the "aligned" message when doing the |
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align-check command (assuming it was succesfull) so you can't judge if |
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any previous attempts was succesful or not (I think that's what you were |
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trying to do if I understand you correctly). |
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> Should I conclude that sda and sdb are |
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> correct and optimized for 4K block drives? |
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Perhaps this may help (I don't have any 4k sector disks so...): |
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http://forums.gentoo.org/viewtopic-t-838522-start-0.html |
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> I never used parted before, so I can easily be making |
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> a mistake [3] or poor assumption? |
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Hm... the only way to be sure is to test it ( or "nuke it from above" ;-) ). |
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I hope I have (accidentally or not) made some sense... :-D |
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Best regards |
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Peter K |
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